Missing RuntimeDirectory in Systemd service file (Ubuntu 24.04 Server)

__Steps to reproduce:__

1. Running InfluxDB v1.11.8
2. Edit the `influxdb.conf` and enable unix socket:
```conf
unix-socket-enabled = true
bind-socket = "/var/run/influxdb/influxdb.sock"
```
3. Using the default `/usr/lib/systemd/system/influxdb.service` file, provided by you.
4. Failing to start InfluxDB!

__Expected behavior:__

Influxdb starting without errors and write the socket file.

__Actual behavior:__

Ubuntu Server 24.04 prohibits the writing of the socket file (`/var/run/influxdb/influxdb.sock`) to disk, because you didn't allow the systemd service file write access to the `/var/run/influxdb` directory..... See fix below!

InfluxDB unable to start in Ubuntu 24.04, because the service file is unable to write the socket file to `/var/run/influxdb` directory.

__Fix:__

The fix is easy, please extend your official `influxdb.service` in your Ubuntu packages with the following:

```ini
[Service]
....
RuntimeDirectory=influxdb
RuntimeDirectoryMode=0755
```

__Config:__
Copy any non-default config values here or attach the full config as a gist or file.

```conf
unix-socket-enabled = true
bind-socket = "/var/run/influxdb/influxdb.sock"
```

__Logs:__

```
Nov 28 17:59:21 ubuntu-server influxd-systemd-start.sh[41891]: InfluxDB API unavailable after 1 attempts...
Nov 28 17:59:22 ubuntu-server influxd-systemd-start.sh[41891]: InfluxDB API unavailable after 2 attempts...
Nov 28 17:59:23 ubuntu-server influxd-systemd-start.sh[41891]: InfluxDB API unavailable after 3 attempts...
Nov 28 17:59:24 ubuntu-server influxd-systemd-start.sh[41891]: InfluxDB API unavailable after 4 attempts...
Nov 28 17:59:25 ubuntu-server influxd-systemd-start.sh[41891]: InfluxDB API unavailable after 5 attempts...
Nov 28 17:59:25 ubuntu-server influxd-systemd-start.sh[41891]: InfluxDB API unavailable after 6 attempts...
Nov 28 17:59:25 ubuntu-server influxd-systemd-start.sh[41891]: InfluxDB API unavailable after 7 attempts...
Nov 28 17:59:25 ubuntu-server influxd-systemd-start.sh[41891]: InfluxDB API unavailable after 8 attempts...
Nov 28 17:59:25 ubuntu-server influxd-systemd-start.sh[41891]: InfluxDB API unavailable after 9 attempts...
Nov 28 17:59:25 ubuntu-server influxd-systemd-start.sh[41891]: InfluxDB API unavailable after 10 attempts...
Nov 28 17:59:25 ubuntu-server influxd-systemd-start.sh[41891]: InfluxDB API unavailable after 11 attempts...
Nov 28 17:59:25 ubuntu-server influxd-systemd-start.sh[41891]: InfluxDB API unavailable after 12 attempts...
Nov 28 17:59:25 ubuntu-server influxd-systemd-start.sh[41891]: InfluxDB API unavailable after 13 attempts..

.. Well.. it won't never start..
```

Inspect /usr/lib/systemd/system/influxdb.service alongside the unix-socket and bind-socket settings shown in the issue. Verify the service creates or permits /var/run/influxdb on Ubuntu 24.04, then confirm InfluxDB starts and writes influxdb.sock successfully.

Written by the indexing model from the issue text.